Little is known about what happens as animals learn to associate meaning with taste, although it is known that gustatory cortex (GC) and amygdala (AMG) are involved in the process. The goal of these experiments is to record simultaneously from these areas as rats learn to associate illness with a taste that they formerly thought palatable (this kind of learning is called conditioned taste aversion, or CTA). Ensembles of GC and AMG single neurons will be recorded through the entire learning process, as the rats progress from being naive to trained. The specific aims of the project are: 1) to determine the aspects of temporal codes in both brain areas that change during learning, as well as how interactions between the areas change; 2) to examine whether GC and AMG are specifically involved in learned reflexes that are produced as the rats try to expel the newly noxious taste; 3) to test whether the inactivation of AMG during training keeps these changes from appearing during testing; and 4) to test whether the development of plasticity in AMG is a specific part of these changes in temporal coding. Overall, this project will shed light on the neural mechanisms underlying an experiential phenomenon that affects (sometimes adversely) the lives of all mammals, including humans.